/*
* Fragment input
*/
int
frag6_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp, *t;
struct ip6_hdr *ip6;
struct ip6_frag *ip6f;
struct ip6q *q6;
struct ip6asfrag *af6, *ip6af, *af6dwn;
#ifdef IN6_IFSTAT_STRICT
struct in6_ifaddr *ia;
#endif
int offset = *offp, nxt, i, next;
int first_frag = 0;
int fragoff, frgpartlen; /* must be larger than u_int16_t */
struct ifnet *dstifp;
u_int8_t ecn, ecn0;
#if 0
char ip6buf[INET6_ADDRSTRLEN];
#endif
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE);
ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset);
#else
IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f));
if (ip6f == NULL)
return (IPPROTO_DONE);
#endif
dstifp = NULL;
#ifdef IN6_IFSTAT_STRICT
/* find the destination interface of the packet. */
if ((ia = ip6_getdstifaddr(m)) != NULL) {
dstifp = ia->ia_ifp;
ifa_free(&ia->ia_ifa);
}
#else
/* we are violating the spec, this is not the destination interface */
if ((m->m_flags & M_PKTHDR) != 0)
dstifp = m->m_pkthdr.rcvif;
#endif
/* jumbo payload can't contain a fragment header */
if (ip6->ip6_plen == 0) {
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset);
in6_ifstat_inc(dstifp, ifs6_reass_fail);
return IPPROTO_DONE;
}
/*
* check whether fragment packet's fragment length is
* multiple of 8 octets.
* sizeof(struct ip6_frag) == 8
* sizeof(struct ip6_hdr) = 40
*/
if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) &&
(((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) {
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
offsetof(struct ip6_hdr, ip6_plen));
in6_ifstat_inc(dstifp, ifs6_reass_fail);
return IPPROTO_DONE;
}
IP6STAT_INC(ip6s_fragments);
in6_ifstat_inc(dstifp, ifs6_reass_reqd);
/* offset now points to data portion */
offset += sizeof(struct ip6_frag);
/*
* RFC 6946: Handle "atomic" fragments (offset and m bit set to 0)
* upfront, unrelated to any reassembly. Just skip the fragment header.
*/
if ((ip6f->ip6f_offlg & ~IP6F_RESERVED_MASK) == 0) {
/* XXX-BZ we want dedicated counters for this. */
IP6STAT_INC(ip6s_reassembled);
in6_ifstat_inc(dstifp, ifs6_reass_ok);
*offp = offset;
return (ip6f->ip6f_nxt);
}
IP6Q_LOCK();
/*
* Enforce upper bound on number of fragments.
* If maxfrag is 0, never accept fragments.
* If maxfrag is -1, accept all fragments without limitation.
*/
if (V_ip6_maxfrags < 0)
;
else if (V_frag6_nfrags >= (u_int)V_ip6_maxfrags)
goto dropfrag;
for (q6 = V_ip6q.ip6q_next; q6 != &V_ip6q; q6 = q6->ip6q_next)
if (ip6f->ip6f_ident == q6->ip6q_ident &&
IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) &&
IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)
#ifdef MAC
&& mac_ip6q_match(m, q6)
#endif
)
break;
if (q6 == &V_ip6q) {
/*
* the first fragment to arrive, create a reassembly queue.
*/
first_frag = 1;
/*
* Enforce upper bound on number of fragmented packets
* for which we attempt reassembly;
* If maxfragpackets is 0, never accept fragments.
* If maxfragpackets is -1, accept all fragments without
* limitation.
*/
if (V_ip6_maxfragpackets < 0)
;
else if (V_frag6_nfragpackets >= (u_int)V_ip6_maxfragpackets)
goto dropfrag;
V_frag6_nfragpackets++;
q6 = (struct ip6q *)malloc(sizeof(struct ip6q), M_FTABLE,
M_NOWAIT);
if (q6 == NULL)
goto dropfrag;
bzero(q6, sizeof(*q6));
#ifdef MAC
if (mac_ip6q_init(q6, M_NOWAIT) != 0) {
free(q6, M_FTABLE);
goto dropfrag;
}
mac_ip6q_create(m, q6);
#endif
frag6_insque(q6, &V_ip6q);
/* ip6q_nxt will be filled afterwards, from 1st fragment */
q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6;
#ifdef notyet
q6->ip6q_nxtp = (u_char *)nxtp;
#endif
q6->ip6q_ident = ip6f->ip6f_ident;
q6->ip6q_ttl = IPV6_FRAGTTL;
q6->ip6q_src = ip6->ip6_src;
q6->ip6q_dst = ip6->ip6_dst;
q6->ip6q_ecn =
(ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
q6->ip6q_unfrglen = -1; /* The 1st fragment has not arrived. */
q6->ip6q_nfrag = 0;
}
/*
* Type0 routing header processing
*
* RFC2292 backward compatibility warning: no support for strict/loose bitmap,
* as it was dropped between RFC1883 and RFC2460.
*/
static int
ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6,
struct ip6_rthdr0 *rh0)
{
int addrs, index;
struct in6_addr *nextaddr, tmpaddr;
const struct ip6aux *ip6a;
if (rh0->ip6r0_segleft == 0)
return (0);
if (rh0->ip6r0_len % 2
#ifdef COMPAT_RFC1883
|| rh0->ip6r0_len > 46
#endif
) {
/*
* Type 0 routing header can't contain more than 23 addresses.
* RFC 2462: this limitation was removed since strict/loose
* bitmap field was deleted.
*/
IP6_STATINC(IP6_STAT_BADOPTIONS);
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
(char *)&rh0->ip6r0_len - (char *)ip6);
return (-1);
}
if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
IP6_STATINC(IP6_STAT_BADOPTIONS);
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
(char *)&rh0->ip6r0_segleft - (char *)ip6);
return (-1);
}
index = addrs - rh0->ip6r0_segleft;
rh0->ip6r0_segleft--;
nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
/*
* reject invalid addresses. be proactive about malicious use of
* IPv4 mapped/compat address.
* XXX need more checks?
*/
if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
IN6_IS_ADDR_V4MAPPED(nextaddr) ||
IN6_IS_ADDR_V4COMPAT(nextaddr)) {
p6stat[IP6_STAT_BADOPTIONS]++;
goto bad;
}
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
IP6_STATINC(IP6_STAT_BADOPTIONS);
goto bad;
}
/*
* Determine the scope zone of the next hop, based on the interface
* of the current hop. [RFC4007, Section 9]
* Then disambiguate the scope zone for the next hop (if necessary).
*/
if ((ip6a = ip6_getdstifaddr(m)) == NULL)
goto bad;
if (in6_setzoneid(nextaddr, ip6a->ip6a_scope_id) != 0) {
IP6_STATINC(IP6_STAT_BADSCOPE);
goto bad;
}
/*
* Swap the IPv6 destination address and nextaddr. Forward the packet.
*/
tmpaddr = *nextaddr;
*nextaddr = ip6->ip6_dst;
in6_clearscope(nextaddr); /* XXX */
ip6->ip6_dst = tmpaddr;
#ifdef COMPAT_RFC1883
if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
else
ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
#else
ip6_forward(m, 1);
#endif
return (-1); /* m would be freed in ip6_forward() */
bad:
m_freem(m);
return (-1);
}
